Opuntioid cacti: declared pests

Page last updated: Thursday, 6 May 2021 - 9:52am

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The opuntioid cacti (except for Austrocylindropuntia vestitaCylindropuntia californica, Opuntia santa-rita) are Declared Pests statewide for Western Australia. This article describes the nature of the plants with links to requirements land owners/occupiers must adhere to and pest control methods.

Form: shrub — perennial

Status: many species are present in WA

The opuntioid cacti Austrocylindropuntia, Cylindropuntia and Opuntia species (except O. ficus-indica) are Weeds of National Significance in Australia (WoNS).


Opuntioid cacti generally have thick fleshy stems. Some larger species, such as Opuntia tomentosa, can have a woody trunk. Cacti can be distinguished from other succulent plants by the presence of areoles, small fleshy, cushion-like structures with trichomes (plant hairs) and, in almost all species, spines or barbed bristles (glochids).

Austrocylindropuntia species are distinguished by having non-segmented cylindrical branches that are of unlimited growth and which produce lateral branches. Their spines are not sheathed. (see Austrocylindropuntia cacti page)

Cylindropuntia species have cylindrical or rope-like branches that are segmented. Their spines are sheathed. (see Cylindropuntia cacti page)

Opuntia species are probably the most easily recognised of the opuntioid cacti, with their large round or oval flattened segments, usually known as pads. They are often referred to collectively as prickly pears or prickly pear cacti. (see Opuntia cacti page)

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Agricultural and economic impact

The major economic impacts of the opuntioid cacti are on the pastoral and grazing industries. The weeds can reduced production and increase economical losses of the grazing industry. Cactus infestations can interfere with mustering and access to watering points; spines can damage hides and contaminate fleeces making shearing extremely difficult. Other costs relate to veterinary and medical costs for the treatment of injuries due to cactus spines injuring livestock and humans.

Opuntioid cacti also impact on horticulture through producing fruit that harbour fruit flies.

Opuntiod cacti are environmental weeds responsible of habitat change and loss of biodiversity by competing with and replacing native vegetation. They can damage environmentally sensitive areas, especially along watercourses; injuring or killing native animals and harbouring vertebrate pests such as foxes and rabbits.

Control and management of infestations (including cost of herbicides, spraying equipment and fencing) can be extremely costly particularly in remote areas.

Opuntioid cacti can restrict access or completely degrading culturally significant sites and landscapes, affecting tourism and recreational activities.

Spines and glochids can cause injuries and serious skin irritation to humans.

Declared pest category

The Western Australian Organism List (WAOL) contains information on the area(s) in which this pest is declared and the control and keeping categories to which it has been assigned in Western Australia (WA). Search for opuntioid cacti in the AOL by using the scientific name Opuntia, Cylindropuntia or Austrocylindropuntia.

Requirements for land owners/occupiers and other persons

Requirements for land owners/occupiers and other persons if this pest is found can be sourced through the declared plant requirements link.

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MyPestGuide™ Reporter
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Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080

Control methods

Report the presence of this organism if it's legal status is prohibited before undertaking a control measure. Control methods for these declared plants can be found through the opuntioid cacti control link.

Further Information

For more information on cacti, download the Opuntioid cacti best practice control manual.

Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080
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